/**
 * Copyright (c) 2014-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

/**
 * This file provides type definitions for use with the Flow type checker.
 *
 * An important caveat when using these definitions is that the types for
 * `Iterable.Keyed`, `Iterable.Indexed`, `Seq.Keyed`, and so on are stubs.
 * When referring to those types, you can get the proper definitions by
 * importing the types `KeyedIterable`, `IndexedIterable`, `KeyedSeq`, etc.
 * For example,
 *
 *     import { Seq } from 'immutable'
 *     import type { IndexedIterable, IndexedSeq } from 'immutable'
 *
 *     const someSeq: IndexedSeq<number> = Seq.Indexed.of(1, 2, 3)
 *
 *     function takesASeq<T, TS: IndexedIterable<T>>(iter: TS): TS {
 *       return iter.butLast()
 *     }
 *
 *     takesASeq(someSeq)
 *
 * @flow
 */

 /*
  * Alias for ECMAScript `Iterable` type, declared in
  * https://github.com/facebook/flow/blob/master/lib/core.js
  *
  * Note that Immutable values implement the `ESIterable` interface.
  */
type ESIterable<T> = $Iterable<T,void,void>;

declare module 'immutable' {
  declare class Iterable<K, V> extends _Iterable<K, V, typeof KeyedIterable, typeof IndexedIterable, typeof SetIterable> {}

  declare class _Iterable<K, V, KI, II, SI> {
    static Keyed:   KI;
    static Indexed: II;
    static Set:     SI;

    static isIterable(maybeIterable: any): boolean;
    static isKeyed(maybeKeyed: any): boolean;
    static isIndexed(maybeIndexed: any): boolean;
    static isAssociative(maybeAssociative: any): boolean;
    static isOrdered(maybeOrdered: any): boolean;

    equals(other: Iterable<K,V>): boolean;
    hashCode(): number;
    get(key: K): V;
    get<V_>(key: K, notSetValue: V_): V|V_;
    has(key: K): boolean;
    includes(value: V): boolean;
    contains(value: V): boolean;
    first(): V;
    last(): V;

    getIn<T>(searchKeyPath: ESIterable<any>, notSetValue: T): T;
    getIn<T>(searchKeyPath: ESIterable<any>): T;
    hasIn(searchKeyPath: ESIterable<any>): boolean;

    toJS(): any;
    toArray(): V[];
    toObject(): { [key: string]: V };
    toMap(): Map<K,V>;
    toOrderedMap(): Map<K,V>;
    toSet(): Set<V>;
    toOrderedSet(): Set<V>;
    toList(): List<V>;
    toStack(): Stack<V>;
    toSeq(): Seq<K,V>;
    toKeyedSeq(): KeyedSeq<K,V>;
    toIndexedSeq(): IndexedSeq<V>;
    toSetSeq(): SetSeq<V>;

    keys(): Iterator<K>;
    values(): Iterator<V>;
    entries(): Iterator<[K,V]>;

    keySeq(): IndexedSeq<K>;
    valueSeq(): IndexedSeq<V>;
    entrySeq(): IndexedSeq<[K,V]>;

    reverse(): this;
    sort(comparator?: (valueA: V, valueB: V) => number): this;

    sortBy<C>(
      comparatorValueMapper: (value: V, key: K, iter: this) => C,
      comparator?: (valueA: C, valueB: C) => number
    ): this;

    groupBy<G>(
      grouper: (value: V, key: K, iter: this) => G,
      context?: any
    ): KeyedSeq<G, this>;

    forEach(
      sideEffect: (value: V, key: K, iter: this) => any,
      context?: any
    ): number;

    slice(begin?: number, end?: number): this;
    rest(): this;
    butLast(): this;
    skip(amount: number): this;
    skipLast(amount: number): this;
    skipWhile(predicate: (value: V, key: K, iter: this) => mixed, context?: any): this;
    skipUntil(predicate: (value: V, key: K, iter: this) => mixed, context?: any): this;
    take(amount: number): this;
    takeLast(amount: number): this;
    takeWhile(predicate: (value: V, key: K, iter: this) => mixed, context?: any): this;
    takeUntil(predicate: (value: V, key: K, iter: this) => mixed, context?: any): this;
    flatten(depth?: number): /*this*/Iterable<any,any>;
    flatten(shallow?: boolean): /*this*/Iterable<any,any>;

    filter(
      predicate: (value: V, key: K, iter: this) => mixed,
      context?: any
    ): this;

    filterNot(
      predicate: (value: V, key: K, iter: this) => mixed,
      context?: any
    ): this;

    reduce<R>(
      reducer: (reduction: R, value: V, key: K, iter: this) => R,
      initialReduction?: R,
      context?: any,
    ): R;

    reduceRight<R>(
      reducer: (reduction: R, value: V, key: K, iter: this) => R,
      initialReduction?: R,
      context?: any,
    ): R;

    every(predicate: (value: V, key: K, iter: this) => mixed, context?: any): boolean;
    some(predicate: (value: V, key: K, iter: this) => mixed, context?: any): boolean;
    join(separator?: string): string;
    isEmpty(): boolean;
    count(predicate?: (value: V, key: K, iter: this) => mixed, context?: any): number;
    countBy<G>(grouper: (value: V, key: K, iter: this) => G, context?: any): Map<G,number>;

    find(
      predicate: (value: V, key: K, iter: this) => mixed,
      context?: any,
    ): ?V;
    find<V_>(
      predicate: (value: V, key: K, iter: this) => mixed,
      context: any,
      notSetValue: V_
    ): V|V_;

    findLast(
      predicate: (value: V, key: K, iter: this) => mixed,
      context?: any,
    ): ?V;
    findLast<V_>(
      predicate: (value: V, key: K, iter: this) => mixed,
      context: any,
      notSetValue: V_
    ): V|V_;


    findEntry(predicate: (value: V, key: K, iter: this) => mixed): ?[K,V];
    findLastEntry(predicate: (value: V, key: K, iter: this) => mixed): ?[K,V];

    findKey(predicate: (value: V, key: K, iter: this) => mixed, context?: any): ?K;
    findLastKey(predicate: (value: V, key: K, iter: this) => mixed, context?: any): ?K;

    keyOf(searchValue: V): ?K;
    lastKeyOf(searchValue: V): ?K;

    max(comparator?: (valueA: V, valueB: V) => number): V;
    maxBy<C>(
      comparatorValueMapper: (value: V, key: K, iter: this) => C,
      comparator?: (valueA: C, valueB: C) => number
    ): V;
    min(comparator?: (valueA: V, valueB: V) => number): V;
    minBy<C>(
      comparatorValueMapper: (value: V, key: K, iter: this) => C,
      comparator?: (valueA: C, valueB: C) => number
    ): V;

    isSubset(iter: Iterable<any, V>): boolean;
    isSubset(iter: ESIterable<V>): boolean;
    isSuperset(iter: Iterable<any, V>): boolean;
    isSuperset(iter: ESIterable<V>): boolean;
  }

  declare class KeyedIterable<K,V> extends Iterable<K,V> {
    static <K,V>(iter?: ESIterable<[K,V]>): KeyedIterable<K,V>;
    static <K,V>(obj?: { [key: K]: V }): KeyedIterable<K,V>;

    @@iterator(): Iterator<[K,V]>;
    toSeq(): KeyedSeq<K,V>;
    flip(): /*this*/KeyedIterable<V,K>;

    mapKeys<K_>(
      mapper: (key: K, value: V, iter: this) => K_,
      context?: any
    ): /*this*/KeyedIterable<K_,V>;

    mapEntries<K_,V_>(
      mapper: (entry: [K,V], index: number, iter: this) => [K_,V_],
      context?: any
    ): /*this*/KeyedIterable<K_,V_>;

    concat(...iters: ESIterable<[K,V]>[]): this;

    map<V_>(
      mapper: (value: V, key: K, iter: this) => V_,
      context?: any
    ): /*this*/KeyedIterable<K,V_>;

    flatMap<K_, V_>(
      mapper: (value: V, key: K, iter: this) => ESIterable<[K_,V_]>,
      context?: any
    ): /*this*/KeyedIterable<K_,V_>;

    flatten(depth?: number): /*this*/KeyedIterable<any,any>;
    flatten(shallow?: boolean): /*this*/KeyedIterable<any,any>;
  }

  declare class IndexedIterable<T> extends Iterable<number,T> {
    static <T>(iter?: ESIterable<T>): IndexedIterable<T>;

    @@iterator(): Iterator<T>;
    toSeq(): IndexedSeq<T>;
    fromEntrySeq<K,V>(): KeyedSeq<K,V>;
    interpose(separator: T): this;
    interleave(...iterables: ESIterable<T>[]): this;
    splice(
      index: number,
      removeNum: number,
      ...values: T[]
    ): this;

    zip<A>(
      a: ESIterable<A>,
      $?: null
    ): IndexedIterable<[T,A]>;
    zip<A,B>(
      a: ESIterable<A>,
      b: ESIterable<B>,
      $?: null
    ): IndexedIterable<[T,A,B]>;
    zip<A,B,C>(
      a: ESIterable<A>,
      b: ESIterable<B>,
      c: ESIterable<C>,
      $?: null
    ): IndexedIterable<[T,A,B,C]>;
    zip<A,B,C,D>(
      a: ESIterable<A>,
      b: ESIterable<B>,
      c: ESIterable<C>,
      d: ESIterable<D>,
      $?: null
    ): IndexedIterable<[T,A,B,C,D]>;
    zip<A,B,C,D,E>(
      a: ESIterable<A>,
      b: ESIterable<B>,
      c: ESIterable<C>,
      d: ESIterable<D>,
      e: ESIterable<E>,
      $?: null
    ): IndexedIterable<[T,A,B,C,D,E]>;

    zipWith<A,R>(
      zipper: (value: T, a: A) => R,
      a: ESIterable<A>,
      $?: null
    ): IndexedIterable<R>;
    zipWith<A,B,R>(
      zipper: (value: T, a: A, b: B) => R,
      a: ESIterable<A>,
      b: ESIterable<B>,
      $?: null
    ): IndexedIterable<R>;
    zipWith<A,B,C,R>(
      zipper: (value: T, a: A, b: B, c: C) => R,
      a: ESIterable<A>,
      b: ESIterable<B>,
      c: ESIterable<C>,
      $?: null
    ): IndexedIterable<R>;
    zipWith<A,B,C,D,R>(
      zipper: (value: T, a: A, b: B, c: C, d: D) => R,
      a: ESIterable<A>,
      b: ESIterable<B>,
      c: ESIterable<C>,
      d: ESIterable<D>,
      $?: null
    ): IndexedIterable<R>;
    zipWith<A,B,C,D,E,R>(
      zipper: (value: T, a: A, b: B, c: C, d: D, e: E) => R,
      a: ESIterable<A>,
      b: ESIterable<B>,
      c: ESIterable<C>,
      d: ESIterable<D>,
      e: ESIterable<E>,
      $?: null
    ): IndexedIterable<R>;

    indexOf(searchValue: T): number;
    lastIndexOf(searchValue: T): number;
    findIndex(
      predicate: (value: T, index: number, iter: this) => mixed,
      context?: any
    ): number;
    findLastIndex(
      predicate: (value: T, index: number, iter: this) => mixed,
      context?: any
    ): number;

    concat(...iters: ESIterable<T>[]): this;

    map<U>(
      mapper: (value: T, index: number, iter: this) => U,
      context?: any
    ): /*this*/IndexedIterable<U>;

    flatMap<U>(
      mapper: (value: T, index: number, iter: this) => ESIterable<U>,
      context?: any
    ): /*this*/IndexedIterable<U>;

    flatten(depth?: number): /*this*/IndexedIterable<any>;
    flatten(shallow?: boolean): /*this*/IndexedIterable<any>;
  }

  declare class SetIterable<T> extends Iterable<T,T> {
    static <T>(iter?: ESIterable<T>): SetIterable<T>;

    @@iterator(): Iterator<T>;
    toSeq(): SetSeq<T>;

    concat(...iters: ESIterable<T>[]): this;

    // `map` and `flatMap` cannot be defined further up the hiearchy, because the
    // implementation for `KeyedIterable` allows the value type to change without
    // constraining the key type. That does not work for `SetIterable` - the value
    // and key types *must* match.
    map<U>(
      mapper: (value: T, value: T, iter: this) => U,
      context?: any
    ): /*this*/SetIterable<U>;

    flatMap<U>(
      mapper: (value: T, value: T, iter: this) => ESIterable<U>,
      context?: any
    ): /*this*/SetIterable<U>;

    flatten(depth?: number): /*this*/SetIterable<any>;
    flatten(shallow?: boolean): /*this*/SetIterable<any>;
  }

  declare class Collection<K,V> extends _Iterable<K,V, typeof KeyedCollection, typeof IndexedCollection, typeof SetCollection> {
    size: number;
  }

  declare class KeyedCollection<K,V> extends Collection<K,V> mixins KeyedIterable<K,V> {
    toSeq(): KeyedSeq<K,V>;
  }

  declare class IndexedCollection<T> extends Collection<number,T> mixins IndexedIterable<T> {
    toSeq(): IndexedSeq<T>;
  }

  declare class SetCollection<T> extends Collection<T,T> mixins SetIterable<T> {
    toSeq(): SetSeq<T>;
  }

  declare class Seq<K,V> extends _Iterable<K,V, typeof KeyedSeq, typeof IndexedSeq, typeof SetSeq> {
    static <K,V>(iter: KeyedSeq<K,V>):   KeyedSeq<K,V>;
    static <T>  (iter: SetSeq<T>):       SetSeq<K,V>;
    static <T>  (iter?: ESIterable<T>):  IndexedSeq<T>;
    static <K,V>(iter: { [key: K]: V }): KeyedSeq<K,V>;

    static isSeq(maybeSeq: any): boolean;

    size: ?number;
    cacheResult(): this;
    toSeq(): this;
  }

  declare class KeyedSeq<K,V> extends Seq<K,V> mixins KeyedIterable<K,V> {
    static <K,V>(iter?: ESIterable<[K,V]>): KeyedSeq<K,V>;
    static <K,V>(iter?: { [key: K]: V }): KeyedSeq<K,V>;
  }

  declare class IndexedSeq<T> extends Seq<number,T> mixins IndexedIterable<T> {
    static <T>(iter?: ESIterable<T>): IndexedSeq<T>;
    static of<T>(...values: T[]): IndexedSeq<T>;
  }

  declare class SetSeq<T> extends Seq<T,T> mixins SetIterable<T> {
    static <T>(iter?: ESIterable<T>): IndexedSeq<T>;
    static of<T>(...values: T[]): SetSeq<T>;
  }

  declare class List<T> extends IndexedCollection<T> {
    static (iterable?: ESIterable<T>): List<T>;

    static isList(maybeList: any): boolean;
    static of<T>(...values: T[]): List<T>;

    set<U>(index: number, value: U): List<T|U>;
    delete(index: number): this;
    remove(index: number): this;
    insert<U>(index: number, value: U): List<T|U>;
    clear(): this;
    push<U>(...values: U[]): List<T|U>;
    pop(): this;
    unshift<U>(...values: U[]): List<T|U>;
    shift(): this;

    update<U>(updater: (value: this) => List<U>): List<U>;
    update<U>(index: number, updater: (value: T) => U): List<T|U>;
    update<U>(index: number, notSetValue: U, updater: (value: T) => U): List<T|U>;

    merge<U>(...iterables: ESIterable<U>[]): List<T|U>;

    mergeWith<U,V>(
      merger: (previous: T, next: U, key: number) => V,
      ...iterables: ESIterable<U>[]
    ): List<T|U|V>;

    mergeDeep<U>(...iterables: ESIterable<U>[]): List<T|U>;

    mergeDeepWith<U,V>(
      merger: (previous: T, next: U, key: number) => V,
      ...iterables: ESIterable<U>[]
    ): List<T|U|V>;

    setSize(size: number): List<?T>;
    setIn(keyPath: ESIterable<any>, value: any): List<T>;
    deleteIn(keyPath: ESIterable<any>, value: any): this;
    removeIn(keyPath: ESIterable<any>, value: any): this;

    updateIn(keyPath: ESIterable<any>, notSetValue: any, value: any): List<T>;
    updateIn(keyPath: ESIterable<any>, value: any): List<T>;

    mergeIn(keyPath: ESIterable<any>, ...iterables: ESIterable<any>[]): List<T>;
    mergeDeepIn(keyPath: ESIterable<any>, ...iterables: ESIterable<any>[]): List<T>;

    withMutations(mutator: (mutable: this) => any): this;
    asMutable(): this;
    asImmutable(): this;

    // Overrides that specialize return types
    map<M>(
      mapper: (value: T, index: number, iter: this) => M,
      context?: any
    ): List<M>;

    flatMap<M>(
      mapper: (value: T, index: number, iter: this) => ESIterable<M>,
      context?: any
    ): List<M>;

    flatten(depth?: number): /*this*/List<any>;
    flatten(shallow?: boolean): /*this*/List<any>;
  }

  declare class Map<K,V> extends KeyedCollection<K,V> {
    static <K, V>(): Map<K, V>;
    static <V>(obj?: {[key: string]: V}): Map<string, V>;
    static <K, V>(iterable?: ESIterable<[K,V]>): Map<K, V>;

    static isMap(maybeMap: any): boolean;

    set<K_, V_>(key: K_, value: V_): Map<K|K_, V|V_>;
    delete(key: K): this;
    remove(key: K): this;
    clear(): this;

    update<K_,V_>(updater: (value: this) => Map<K_,V_>): Map<K_,V_>;
    update<V_>(key: K, updater: (value: V) => V_): Map<K,V|V_>;
    update<V_>(key: K, notSetValue: V_, updater: (value: V) => V_): Map<K,V|V_>;

    merge<K_,V_>(
      ...iterables: (ESIterable<[K_,V_]> | { [key: K_]: V_ })[]
    ): Map<K|K_,V|V_>;

    mergeWith<K_,W,X>(
      merger: (previous: V, next: W, key: number) => X,
      ...iterables: ESIterable<W>[]
    ): Map<K,V|W|X>;

    mergeDeep<K_,V_>(
      ...iterables: (ESIterable<[K_,V_]> | { [key: K_]: V_ })[]
    ): Map<K|K_,V|V_>;

    mergeDeepWith<K_,W,X>(
      merger: (previous: V, next: W, key: number) => X,
      ...iterables: ESIterable<W>[]
    ): Map<K,V|W|X>;

    setIn(keyPath: ESIterable<any>, value: any): Map<K,V>;
    deleteIn(keyPath: ESIterable<any>, value: any): this;
    removeIn(keyPath: ESIterable<any>, value: any): this;

    updateIn(keyPath: ESIterable<any>, notSetValue: any, value: any): Map<K,V>;
    updateIn(keyPath: ESIterable<any>, value: any): Map<K,V>;

    mergeIn(keyPath: ESIterable<any>, ...iterables: ESIterable<any>[]): Map<K,V>;
    mergeDeepIn(keyPath: ESIterable<any>, ...iterables: ESIterable<any>[]): Map<K,V>;

    withMutations(mutator: (mutable: this) => any): this;
    asMutable(): this;
    asImmutable(): this;

    // Overrides that specialize return types

    map<V_>(
      mapper: (value: V, key: K, iter: this) => V_,
      context?: any
    ): Map<K,V_>;

    flatMap<K_,V_>(
      mapper: (value: V, key: K, iter: this) => ESIterable<[K_,V_]>,
      context?: any
    ): Map<K_,V_>;

    flip(): Map<V,K>;

    mapKeys<K_>(
      mapper: (key: K, value: V, iter: this) => K_,
      context?: any
    ): Map<K_,V>;

    flatten(depth?: number): /*this*/Map<any,any>;
    flatten(shallow?: boolean): /*this*/Map<any,any>;
  }

  // OrderedMaps have nothing that Maps do not have. We do not need to override constructor & other statics
  declare class OrderedMap<K,V> extends Map<K,V> {
    static isOrderedMap(maybeOrderedMap: any): bool;
  }

  declare class Set<T> extends SetCollection<T> {
    static <T>(iterable?: ESIterable<T>): Set<T>;

    static isSet(maybeSet: any): boolean;
    static of<T>(...values: T[]): Set<T>;
    static fromKeys<T>(iter: ESIterable<[T,any]>): Set<T>;
    static fromKeys(iter: { [key: string]: any }): Set<string>;

    add<U>(value: U): Set<T|U>;
    delete(value: T): this;
    remove(value: T): this;
    clear(): this;
    union<U>(...iterables: ESIterable<U>[]): Set<T|U>;
    merge<U>(...iterables: ESIterable<U>[]): Set<T|U>;
    intersect<U>(...iterables: ESIterable<U>[]): Set<T&U>;
    subtract<U>(...iterables: ESIterable<U>[]): Set<T>;

    withMutations(mutator: (mutable: this) => any): this;
    asMutable(): this;
    asImmutable(): this;

    // Overrides that specialize return types

    map<M>(
      mapper: (value: T, value: T, iter: this) => M,
      context?: any
    ): Set<M>;

    flatMap<M>(
      mapper: (value: T, value: T, iter: this) => ESIterable<M>,
      context?: any
    ): Set<M>;

    flatten(depth?: number): /*this*/Set<any>;
    flatten(shallow?: boolean): /*this*/Set<any>;
  }

  // OrderedSets have nothing that Sets do not have. We do not need to override constructor & other statics
  declare class OrderedSet<T> extends Set<T> {
    static isOrderedSet(maybeOrderedSet: any): bool;
  }

  declare class Stack<T> extends IndexedCollection<T> {
    static <T>(iterable?: ESIterable<T>): Stack<T>;

    static isStack(maybeStack: any): boolean;
    static of<T>(...values: T[]): Stack<T>;

    peek(): T;
    clear(): this;
    unshift<U>(...values: U[]): Stack<T|U>;
    unshiftAll<U>(iter: ESIterable<U>): Stack<T|U>;
    shift(): this;
    push<U>(...values: U[]): Stack<T|U>;
    pushAll<U>(iter: ESIterable<U>): Stack<T|U>;
    pop(): this;

    withMutations(mutator: (mutable: this) => any): this;
    asMutable(): this;
    asImmutable(): this;

    // Overrides that specialize return types

    map<U>(
      mapper: (value: T, index: number, iter: this) => U,
      context?: any
    ): Stack<U>;

    flatMap<U>(
      mapper: (value: T, index: number, iter: this) => ESIterable<U>,
      context?: any
    ): Stack<U>;

    flatten(depth?: number): /*this*/Stack<any>;
    flatten(shallow?: boolean): /*this*/Stack<any>;
  }

  declare function Range(start?: number, end?: number, step?: number): IndexedSeq<number>;
  declare function Repeat<T>(value: T, times?: number): IndexedSeq<T>;

  //TODO: Once flow can extend normal Objects we can change this back to actually reflect Record behavior.
  // For now fallback to any to not break existing Code
  declare class Record<T: Object> {
    static <T: Object>(spec: T, name?: string): /*T & Record<T>*/any;
    get<A>(key: $Keys<T>): A;
    set<A>(key: $Keys<T>, value: A): /*T & Record<T>*/this;
    remove(key: $Keys<T>): /*T & Record<T>*/this;
  }

  declare function fromJS(json: any, reviver?: (k: any, v: Iterable<any,any>) => any): any;
  declare function is(first: any, second: any): boolean;
}
